French IGN 1:50,000 maps - now with UTM grids?

Rob said:

Hi, I'm trying to find out if the French maps of the Pyrenees (the
1:50,000 ones) for walking now have a GPS compatiable UTM grid on them?

I have the entire set of 1:50,000 Carte de Randonnees, except No 9.
They have two distinct grids, but I cannot make head or tail of
either. One grid, *drawn* on the map, shows areas of about 70 sq Km;
the other *marked* at the edges of the map, shows areas of 25 sq Km.

I expect the former is based on lines of longitude and latitude, but
does not seem to match the 1:250,000 Michelin long and lat grid. The
other seems to be a national grid of some description as some numbers
are quite high.

Pic de Perdiguere, for example, has a GR of 451,045, meaning, I
assume, about 450 Km east of some point and 45 Km north of some point
(somewhere in north-western Spain!)

C L Imber said:

Rob said:

Hi, I'm trying to find out if the French maps of the Pyrenees (the
1:50,000 ones) for walking now have a GPS compatiable UTM grid on them?

I have the entire set of 1:50,000 Carte de Randonnees, except No 9.
They have two distinct grids, but I cannot make head or tail of
either. One grid, *drawn* on the map, shows areas of about 70 sq Km;
the other *marked* at the edges of the map, shows areas of 25 sq Km.

I expect the former is based on lines of longitude and latitude, but
does not seem to match the 1:250,000 Michelin long and lat grid. The
other seems to be a national grid of some description as some numbers
are quite high.

Pic de Perdiguere, for example, has a GR of 451,045, meaning, I
assume, about 450 Km east of some point and 45 Km north of some point
(somewhere in north-western Spain!)

Are there any sources for downloading French maps, do you know?
--
R
o
o
n
e
y

"I always knew the entire Green party were nutters" - Ken Livingstone

Rooney said:

C L Imber said:

Rob said:

Hi, I'm trying to find out if the French maps of the Pyrenees (the
1:50,000 ones) for walking now have a GPS compatiable UTM grid on them?

I have the entire set of 1:50,000 Carte de Randonnees, except No 9.
They have two distinct grids, but I cannot make head or tail of
either. One grid, *drawn* on the map, shows areas of about 70 sq Km;
the other *marked* at the edges of the map, shows areas of 25 sq Km.

I expect the former is based on lines of longitude and latitude, but
does not seem to match the 1:250,000 Michelin long and lat grid. The
other seems to be a national grid of some description as some numbers
are quite high.

Pic de Perdiguere, for example, has a GR of 451,045, meaning, I
assume, about 450 Km east of some point and 45 Km north of some point
(somewhere in north-western Spain!)

Are there any sources for downloading French maps, do you know?

http://www.viamichelin.com/viamichelin/gbr/tpl/hme/MaHomePage.htm

Not much good for the hills.

Rob said:

Hi, I'm trying to find out if the French maps of the Pyrenees (the
1:50,000 ones) for walking now have a GPS compatiable UTM grid on them?

I understand they didnt not too long ago, but the 1:25k have been
updated recently.

I haven't looked at one more recent than a few years old but AFAIK the
Pyrenees 50k maps from the IGN are still not marked with a UTM grid.
There are some other maps in the same series but produced by the ICC
(Institute Cartographic de Catalunya ) that _do_ have a UTM grid. These
are numbered 20, 21,22,... whereas the IGN ones in the series are
numbered 1, 2, ..., 11. The ICC maps straddle the border and therefore
cover Spain as well as France and are a better bet for a Pyreneean jaunt
IMHO. Stanfords do them all, but there are probably cheaper online
outlets in the UK if you hunt around.

Hth,

--
Boo

C L Imber said:

Rooney said:

C L Imber said:

On 19 May 2005 04:03:17 -0700, "Rob" <[email hidden]> wrote:

>Hi, I'm trying to find out if the French maps of the Pyrenees (the
>1:50,000 ones) for walking now have a GPS compatiable UTM grid on them?

I have the entire set of 1:50,000 Carte de Randonnees, except No 9.
They have two distinct grids, but I cannot make head or tail of
either. One grid, *drawn* on the map, shows areas of about 70 sq Km;
the other *marked* at the edges of the map, shows areas of 25 sq Km.

I expect the former is based on lines of longitude and latitude, but
does not seem to match the 1:250,000 Michelin long and lat grid. The
other seems to be a national grid of some description as some numbers
are quite high.

Pic de Perdiguere, for example, has a GR of 451,045, meaning, I
assume, about 450 Km east of some point and 45 Km north of some point
(somewhere in north-western Spain!)

Are there any sources for downloading French maps, do you know?

http://www.viamichelin.com/viamichelin/gbr/tpl/hme/MaHomePage.htm

Not much good for the hills.

Cheers.
--
R
o
o
n
e
y

"I always knew the entire Green party were nutters" - Ken Livingstone

On 19/5/05 12:03, in article
[email hidden], "Rob"

Quoted message said:

Hi, I'm trying to find out if the French maps of the Pyrenees (the
1:50,000 ones) for walking now have a GPS compatiable UTM grid on them?

Well, as of last week in Stanfords the answer seems to be no. If you want
to take a GPS then you will have to take the 1:25 series, Carte Bleu.

In many ways you will only need the 1:50 maps if you are doing the main
routes in the High Pyrenees. But I bought a GPS after getting lost in mist,
in the Pyrenees a couple of years ago. I took the GPS back last year and
didn't use it once in 2 weeks! I think it would be very useful in the
Basque areas where there is a strong chance of heavy mist that can take all
day to clear.

Which area are you considering going to?

--
Andy Howell
Birmingham, UK

To mail simply put back the dots ...

Thanks for that. I'm planning on walking as much of the HRP as time
and money allows, it all depends on what I can earn this summer (I'm a
student) and then whether I have got a proper job offer after uni. Just
looking into it really.

One possible way I have conisidered would be to get all the maps, plan
your route, get the co-ordinates in the Lambert system using a program
like gartrip, use it to convert them to UTM system, and then upload
them to your GPS. In theory it would tell you where you were in
relation to a fixed point, marked on your map.

Obviously it'd require a computer linkable GPS with a decent memory,
could get confusing, and therefore a bit of an expensive toy 95% of the
time.

Rob

Andy Howell said:

On 19/5/05 12:03, in article
[email hidden], "Rob"

Quoted message said:

Hi, I'm trying to find out if the French maps of the Pyrenees (the
1:50,000 ones) for walking now have a GPS compatiable UTM grid on

them?

Quoted message said:

Well, as of last week in Stanfords the answer seems to be no. If you

want

Quoted message said:

to take a GPS then you will have to take the 1:25 series, Carte Bleu.

In many ways you will only need the 1:50 maps if you are doing the

main

Quoted message said:

routes in the High Pyrenees. But I bought a GPS after getting lost in

mist,

Quoted message said:

in the Pyrenees a couple of years ago. I took the GPS back last year

and

Quoted message said:

didn't use it once in 2 weeks! I think it would be very useful in

the

Quoted message said:

Basque areas where there is a strong chance of heavy mist that can

take all

Quoted message said:

day to clear.

Which area are you considering going to?

--
Andy Howell
Birmingham, UK

To mail simply put back the dots ...

C L Imber said:

Rob said:

Hi, I'm trying to find out if the French maps of the Pyrenees (the
1:50,000 ones) for walking now have a GPS compatiable UTM grid on them?

The following probably won't help with the original question as I haven't
got any 1:50k IGN maps, but...

Quoted message said:

I have the entire set of 1:50,000 Carte de Randonnees, except No 9.
They have two distinct grids, but I cannot make head or tail of
either. One grid, *drawn* on the map, shows areas of about 70 sq Km;
the other *marked* at the edges of the map, shows areas of 25 sq Km.

....from a 1992 revision 1:25k (revamped serie bleue, "les cartes
tourisiques locales"😉, it seems as if the two systems used are

(a) a grid printed within the map giving degrees latitude and longitude
relative to the /Paris/ meridian. Since parallels are, err, parallel,
you should be able to get the "proper" longitude by finding out how far
east the Paris observatory is from Greenwich. The blue and black numbers
on the inside of the margin are the corrections needed for two different
"Lambert zones", which I think are two differently orientated overlapping
grid systems for different strips of France. This would be necessary as
France covers a larger range of longitude than Great Britain, making the
distortions from flattening out a section of spherical surface into
a two-dimensional map worse than they are here (just as it wouldn't be
practical to use the same grid for both Great Britain and Ireland).
My Geko doesn't know about Lambert zones, but then it has never been
to France...

(b) is the numbers printed on the outside of the margin. These
apparently refer to UTM coordinates, Mercator zone 31 (for a map of the
Cevennes in SE France). The Mercator zone is needed for the same reason
as the Lambert zones, but I think you don't need to specify which zone
you are in because UTM defines which grid (Mercator zone) is to be used
for which range of longitudes. Yes, here they are:
http://www.dmap.co.uk/utmworld.htm. So the GPS doesn't need to be told.

Disclaimer: My French is dodgy.

Quoted message said:

Pic de Perdiguere, for example, has a GR of 451,045, meaning, I
assume, about 450 Km east of some point and 45 Km north of some point
(somewhere in north-western Spain!)

The origin being outside the country seems to make sense as you would
have negative coordinates for some places otherwise. The OS grid origin
isn't in Great Britain either.
--
Rudi Winter, Aberystwyth, Wales

On 25/5/05 13:12, in article [email hidden], "Rudi

Winter said:

Disclaimer: My French is dodgy.

It takes a while to work out how to use the GPS on the 1:25 maps.

IMPORTANT TIP. Make sure that you work out how the system works before you
get high in the hills !!!

If I remember I'll post a little guide. It's nowhere near as
straightforward as you think. There are non of those sensible grids that
you get on OS maps!

--
Andy Howell
Birmingham, UK

To mail simply put back the dots ...

Andy Howell andy.howellNOSPAM@ecotrenddotorgdotuk said:

On 25/5/05 13:12, in article [email hidden], "Rudi

Winter said:

Disclaimer: My French is dodgy.

Andy - thanks for spotting the one important sentence ;-)

Quoted message said:

If I remember I'll post a little guide. It's nowhere near as
straightforward as you think. There are non of those sensible grids that
you get on OS maps!

Go on then! I'm sure many of us would be interested, and France is always
worth a trip for some good walking.
--
Rudi Winter, Aberystwyth, Wales

On 26/5/05 14:03, in article [email hidden], "Rudi

Winter said:

Go on then! I'm sure many of us would be interested, and France is always
worth a trip for some good walking.

The IGN maps (1:25) are now marked 'Compatible GPS', but it takes a while to
work out what this means!

The maps do have a grid, but the grid numbers are not printed actually on
the map as they are with OS. The co-ordinates are only on the edge of the
maps, which means that you have to have the fully open in order to do
anything with them - which is a bit of a pain.

Study the edges a bit more and you will see two sets of co-ordinates. Some
blue co-ordinates line up with a normal blue grid. A black set of
coordinates lines up with a series of occasional black lines which run true
to the terrain and are not square across the map! Now this is the good bit.

It is the black co-ordinates that you need! These, mostly, do not relate to
a line and so you have to make approximations working on their relation to
the blue grid! (Following this?).

Reading a reference off the map you will end-up with something like this:

3072 471

Now your GPS will only give you two sets of 3 co-ords. It is the 3 at the
beginning of the first set that is important.

The French grid is broken down into 4 sectors. The High Pyrenees are in Grid
Sector 3. But you try finding this out on the map itself.

The significance of this is this:

When you re-set your GPS to French co-ordinates it asks you what zone you
are in, 1-4. This is very confusing if you are doing this without knowing
how the maps work. Enter 3 and you up and running. Except ...

.... Take your GPS reading. It will be something like 072 471 for our
co-ordinates. But looking down the left hand side of the map your
co-ordinate will read 3072. The three is - of course - the sector. But
this is only listed on one set of co-ordinates!

My GPS (Magallen) tends to give a grid as III 072 471.

Now this is not that intuitive and it takes a while to get used to. This is
what you should do.

When you arrive find a place on the map where you know where you are - camp
site, etc. Work out the grid reference according to the map. And then take
a spot reading from the GPS and compare the two.

Easy. Well remember that there is a second set of co-ords that are in blue,
and with a blue grid, there is a temptation to think that these are the ones
you want.

Play around with this until you can remember what you are doing!

Happily, you rarely need a GPS on the High Route. I bought mine because I
got lost on the GR10 the year before. People assure me that this is
impossible, but I managed it! (got lost in the French equivalent of a
bloody forestry commission plantation!).

There. Finished !!!

--
Andy Howell
Birmingham, UK

To mail simply put back the dots ...

On Thu, 26 May 2005 21:10:06 GMT, Andy Howell
<andy.howellNOSPAM@ecotrendDOTorgDOTuk> wrote:

[...]

Quoted message said:

The IGN maps (1:25) are now marked 'Compatible GPS', but it takes a while to
work out what this means!

<snippy>

Wow! Terrifying... I've saved it, just in case. Many thanks for
explaining 🙂

Best wishes,
--
,,
(**)PeeWiglet~~
/ \ / \ pee AT [guessthisbit].co.uk

In article <BEBBF9BF.43971%andy.howellNOSPAM@ecotrendDOTorgDOTuk>, Andy
Howell <andy.howellNOSPAM@ecotrendDOTorgDOTuk.?.invalid> writes

Quoted message said:

On 26/5/05 14:03, in article [email hidden], "Rudi

Winter said:

Go on then! I'm sure many of us would be interested, and France is always
worth a trip for some good walking.

The IGN maps (1:25) are now marked 'Compatible GPS', but it takes a while to
work out what this means!

The maps do have a grid, but the grid numbers are not printed actually on
the map as they are with OS. The co-ordinates are only on the edge of the
maps, which means that you have to have the fully open in order to do
anything with them - which is a bit of a pain.

Study the edges a bit more and you will see two sets of co-ordinates. Some
blue co-ordinates line up with a normal blue grid. A black set of
coordinates lines up with a series of occasional black lines which run true
to the terrain and are not square across the map! Now this is the good bit.

It is the black co-ordinates that you need! These, mostly, do not relate to
a line and so you have to make approximations working on their relation to
the blue grid! (Following this?).

Reading a reference off the map you will end-up with something like this:

3072 471

Now your GPS will only give you two sets of 3 co-ords. It is the 3 at the
beginning of the first set that is important.

The French grid is broken down into 4 sectors. The High Pyrenees are in Grid
Sector 3. But you try finding this out on the map itself.

The significance of this is this:

When you re-set your GPS to French co-ordinates it asks you what zone you
are in, 1-4. This is very confusing if you are doing this without knowing
how the maps work. Enter 3 and you up and running. Except ...

... Take your GPS reading. It will be something like 072 471 for our
co-ordinates. But looking down the left hand side of the map your
co-ordinate will read 3072. The three is - of course - the sector. But
this is only listed on one set of co-ordinates!

My GPS (Magallen) tends to give a grid as III 072 471.

Now this is not that intuitive and it takes a while to get used to. This is
what you should do.

When you arrive find a place on the map where you know where you are - camp
site, etc. Work out the grid reference according to the map. And then take
a spot reading from the GPS and compare the two.

Easy. Well remember that there is a second set of co-ords that are in blue,
and with a blue grid, there is a temptation to think that these are the ones
you want.

Play around with this until you can remember what you are doing!

Happily, you rarely need a GPS on the High Route. I bought mine because I
got lost on the GR10 the year before. People assure me that this is
impossible, but I managed it! (got lost in the French equivalent of a
bloody forestry commission plantation!).

There. Finished !!!

Or use the blue grid with your GPS set to UTM & WGS 84 for a much easier
life :-)

The blue grid is the addition they made to make the maps "GPS
Compatible" or whatever they call it.

--

Dominic Sexton

Andy Howell andy.howellNOSPAM@ecotrenddotorgdotuk said:

On 26/5/05 14:03, in article [email hidden], "Rudi

Winter said:

Go on then! I'm sure many of us would be interested, and France is always
worth a trip for some good walking.

[GPS use with French maps tutorial]

Quoted message said:

There. Finished !!!

Thanks, Andy - will try it out when I'm over there next.
--
Rudi Winter, Aberystwyth, Wales

On 27/5/05 07:46, in article [email hidden],

Peewiglet said:

Wow! Terrifying... I've saved it, just in case. Many thanks for
explaining 🙂

At some time, soon, I'm going to do this properly and put it on a web page!

--
Andy Howell
Birmingham, UK

To mail simply put back the dots ...

On 27/5/05 10:12, in article [email hidden], "Dominic

Sexton said:

Or use the blue grid with your GPS set to UTM & WGS 84 for a much easier
life :-)

It's not always that much easier. Using my Magellan - and following the
instructions for France - is how I came across what I did!

The biggest problem with these maps is really the way the grid is indicated.
They could really learn from the UK tradition of overlaying the co-ords on
the actual map itself!

--
Andy Howell
Birmingham, UK

To mail simply put back the dots ...

On 25/5/05 13:12, in article [email hidden], "Rudi

Winter said:

...from a 1992 revision 1:25k (revamped serie bleue, "les cartes
tourisiques locales"😉, it seems as if the two systems used are

Now that is really useful!

But the problem is this:

Your GPS tells you that you can simply set it up to France. So you think,
fine. Get there and then start exploring. A wild camp (or even a camp
site) is not the best place to do this! And of course you can't really
check the data whilst in the UK !!!

I shall explore this thoroughly and report back!

--
Andy Howell
Birmingham, UK

To mail simply put back the dots ...

Andy Howell said:

On 27/5/05 10:12, in article [email hidden], "Dominic

Sexton said:

Or use the blue grid with your GPS set to UTM & WGS 84 for a much easier
life :-)

It's not always that much easier. Using my Magellan - and following the
instructions for France - is how I came across what I did!

The biggest problem with these maps is really the way the grid is indicated.
They could really learn from the UK tradition of overlaying the co-ords on
the actual map itself!

But that is fairly recent. I can remember OS maps with the grid
numbers only on the margins. Indeed I have a Yorkshire Dales Touring
1" map in my hand now which is copyright 1998 which like that.
--
Phil Cook looking north over the park to the "Westminster Gasworks"

Quoted message said:

Or use the blue grid with your GPS set to UTM & WGS 84 for a much easier
life :-)

Complete and correct :-)

--
Boo